# Draft California 2012 Integrated Report( 303(d) List/305(b) Report)

# Supporting Information

## Regional Board 6 - Lahontan Region

Water Body Name: | Carson River, West Fork (Headwaters to Woodfords)
Water Body ID: | CAR6332001420000207111737
Water Body Type: | River & Stream

DECISION ID | 19180 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Nitrate
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2021
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess pollutant. Five out of 15 samples exceed the water quality objective. The water quality objective for nitrate as nitrogen for West Fork Carson River at Woodfords is a site specific objective of 0.02 mg/L as a mean of monthly means. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Five of 15 samples exceeded the MOMM datapoints and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 19180, Nitrate | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 31669
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 9
Number of Exceedances: | 2
Data and Information Type: | Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: | Two out of 9 annual means of monthly means exceeded the water quality objective for nitrate as nitrogen expressed as an annual mean of monthly means. A total of 102 samples were collected from the two sites.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The site specific objective for West Fork Carson River at Woodfords for nitrate as nitrogen is is 0.02 mg/L as means of monthly means.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at SW-01 Carson River, W Fork, Crystal Springs Rd
Temporal Representation: | Samples were collected monthly from January 2002 to June 2010.
Environmental Conditions: |
QAPP Information: | Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 19180, Nitrate | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27604
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 2
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The USGS sampled this station under the Region 6 SWAMP program between 2003 and 2005. Data were collected for nitrate plus nitrite (as N). A smaller number of samples collected for nitrite alone were all below the detection level. Assuming the nitrate plus nitrite concentrations to be representative of nitrate, concentrations in 10 samples ranged from below the detection level (one sample) to 0.084 mg/L. Calculated means of monthly means for nitrate were as follows: for 2003, 0.019 mg/L; for 2004, 0.023 mg/L, and for 2005, 0.027 mg/L.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The water quality objective for nitrate (as N) in this segment is 0.02 mg/L, expressed as an annual mean of monthly means. This is a running average incorporating historical data.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Quarterly samples (3 to 4 per year) were collected between April 2003 and August 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 19180, Nitrate | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32286
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | None of 2 annual means of monthly means exceeded the water quality objective for nitrate as nitrogen expressed as an annual mean of monthly means. Nitrate as N was calculated by subtracting nitrite as N data from nitrate + nitrite as N data when they were collected on the same day. Thirty-four pairs of samples were collected.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-14 of the Basin Plan states that the water quality objective for nitrate as nitrogen for West Fork Carson River at Woodfords is 0.02 mg/L as a mean of monthly means.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at West Fork Carson River below Willow Creek (633WCR002).
Temporal Representation: | Samples were collected from June 2006 through December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19180, Nitrate | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27601
Pollutant: | Nitrate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | This segment was placed on the Section 303(d) list in 2002 on the basis of calculations by RWQCB staff using data collected by the South Tahoe Public Utility District between 1981 and 2000. The mean of monthly means for nitrate in 2000 was 0.04 mg/L, exceeding the objective.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The water quality objective for nitrate (as N) in this segment is 0.02 mg/L, expressed as an annual mean of monthly means. This is a running average incorporating historical data.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The South Tahoe PUD data were collected in a diversion ditch upstream of the USGS gage at Woodfords.
Temporal Representation: | The South Tahoe PUD samples were collected approximately monthly between 1981 and 2000.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The South Tahoe Public Utility District maintains its own laboratory and has a quality assurance program acceptable to the RWQCB.
QAPP Information Reference(s):

DECISION ID | 18221 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Nitrogen
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2019
Impairment from Pollutant or Pollution: | Pollution
Regional Board Staff Conclusion: | This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Seven lines of evidence are available in the administrative record to assess pollutant. Since the original listing which was based on violations of the MOMM site specific objective for total Kjeldahl nitrogen (TKN) and total nitrogen, lines of evidence for TKN and Nitrogen were considered for this decision for consistency. Ten out of 15 samples exceed the water quality objective for TKN and two of six samples exceed the water quality objective for total nitrogen. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Ten out of 15 samples exceed the water quality objective for TKN and two of six samples exceed the water quality objective for total nitrogen and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 18221, Nitrogen | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27599
Pollutant: | Total Nitrogen as N
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | This segment was placed on the Section 303(d) list in 2002 on the basis of calculations by RWQCB staff using data collected by the South Tahoe Public Utility District between 1981 and 2000. The mean of monthly means for total nitrogen in 2000 was 0.20 mg/L, exceeding the objective.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The water quality objective for total nitrogen in this segment is 0.15 mg/L, expressed as an annual mean of monthly means. This is a running average incorporating historical data.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The South Tahoe PUD data were collected in a diversion ditch upstream of the USGS gage at Woodfords.
Temporal Representation: | The South Tahoe PUD samples were collected approximately monthly between 1981 and 2000.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The South Tahoe Public Utility District maintains its own laboratory and has a quality assurance program acceptable to the RWQCB.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 18221, Nitrogen | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27602
Pollutant: | Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | This segment was placed on the Section 303(d) list in 2002 on the basis of calculations by RWQCB staff using data collected by the South Tahoe Public Utility District between 1981 and 2000. The mean of monthly means for total Kjeldahl nitrogen in 2000 was 0.20 mg/L, exceeding the objective.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The water quality objective for total Kjeldahl nitrogen in this segment is 0.13 mg/L, expressed as an annual mean of monthly means. This is a running average incorporating historical data.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The South Tahoe PUD data were collected in a diversion ditch upstream of the USGS gage at Woodfords.
Temporal Representation: | The South Tahoe PUD samples were collected approximately monthly between 1981 and 2000.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The South Tahoe Public Utility District maintains its own laboratory and has a quality assurance program acceptable to the RWQCB.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 18221, Nitrogen | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27603
Pollutant: | Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 2
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The USGS sampled this station under the Region 6 SWAMP program between 2003 and 2005. Concentrations of TKN in 10 samples ranged from 0.04 to 0.19 mg/L. Calculated means of monthly means were as follows: for 2003, 0.11 mg/L; for 2004, 0.15 mg/L; for 2005, 0.18 mg/L.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The water quality objective for total Kjeldahl nitrogen in this segment is 0.13 mg/L, expressed as an annual mean of monthly means. This is a running average incorporating historical data.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Samples were collected quarterly (3 to 4 per year) between April 2003 and August 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 18221, Nitrogen | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27605
Pollutant: | Total Nitrogen as N
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The USGS sampled this station under the Region 6 SWAMP program between 2003 and 2005. Total Nitrogen was calculated from reported results for total Kjeldahl nitrogen and nitrite plus nitrate. Calculated total N concentrations in 10 quarterly samples ranged from 0.046 to 0.204 mg/L. Calculated means of monthly means were as follows: for 2003, 0.132 mg/L; for 2004, 0.146 mg/L; for 2005, 0.176 mg/L.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The water quality objective for total nitrogen in this segment is 0.15 mg/L, expressed as an annual mean of monthly means. This is a running average incorporating historical data.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled..
Temporal Representation: | Quarterly samples (3 to 4 per year) were collected between April 2003 and August 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 18221, Nitrogen | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 31668
Pollutant: | Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 9
Number of Exceedances: | 7
Data and Information Type: | Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: | Seven out of 9 annual means of monthly means exceeded the water quality objective for Total Kjeldahl Nitrogen expressed as an annual mean of monthly means. A total of 102 samples were collected from the two sites.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The site specific objective for West Fork Carson River at Woodfords for Total Kjeldahl Nitrogen is 0.13 mg/L as means of monthly means.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at SW-01 Carson River, W Fork, Crystal Springs Rd.
Temporal Representation: | Samples were collected monthly from January 2002 to June 2010.
Environmental Conditions: |
QAPP Information: | Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 18221, Nitrogen | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32355
Pollutant: | Total Nitrogen as N
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | None of 2 annual means of monthly means exceeded the water quality objective for total nitrogen. Total nitrogen was calculated by summing nitrate + nitrite as N data with TKN data when they were collected on the same day. Thirty-four pairs of samples were collected from the monitoring location.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-14 of the Basin Plan states that the water quality objective for Total N for West Fork Carson River at Woodfords is 0.15 mg/L as a mean of monthly means.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at West Fork Carson River below Willow Creek (633WCR002).
Temporal Representation: | Samples were collected from June 2006 through December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 18221, Nitrogen | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 34487
Pollutant: | Total Kjeldahl Nitrogen (TKN)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 0 of 2 means of monthly means exceed the water quality objective for TKN. 7 monthly means were averaged for 2006 before comparing with the mean of monthly mean TKN objective. 12 monthly means were averaged for 2007 to compare with the mean of monthly mean TKN objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-14 of the Basin Plan states that the water quality objective for TKN for West Fork Carson River at Woodfords is 0.13 mg/L as a mean of monthly means.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at West Fork Carson River below Willow Creek (633WCR002).
Temporal Representation: | Samples were collected from June 2006 through December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 19993 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Phosphorus
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2019
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. Five lines of evidence are available in the administrative record to assess pollutant. The original listing for this waterbody pollutant combination was based on placeholder data associated with the 2006 LOE (LOE ID 4596). The 2010 LOE (LOE ID 27595) is not used in the final use rating because the samples should not be used in the assessment because of an error in the SWAMP QAPP regarding holding times for total phosphorus samples. Eight of 15 samples (based on LOE IDs 27592, 34486, 31691) exceed the water quality objective, which is a site specific objective of 0.02 mg/L, expressed as a mean of monthly means, for West Fork Carson River at Woodfords. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. LOE ID 27595 is not used in the assessment or final use rating because of an error in the SWAMP QAPP regarding holding times for total phosphorus samples. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the full range of seasonal and annual variation expected in streamflows and constituent concentrations in streams of the Lahontan Region. 3. Eight of 15 samples exceeded the site specific objective and this exceeds the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

Line of Evidence (LOE) for Decision ID 19993, Phosphorus | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4596
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.
Data Reference: | Placeholder reference pre-2006 303(d)
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | Unspecified
Objective/Criterion Reference: | Placeholder reference pre-2006 303(d)
Evaluation Guideline: | Unspecified
Guideline Reference: | Placeholder reference pre-2006 303(d)
Spatial Representation: | Unspecified
Temporal Representation: | Unspecified
Environmental Conditions: | Unspecified
QAPP Information: | Unspecified
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 19993, Phosphorus | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 34486
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | 2 of 2 means of monthly means exceed the water quality objective for Total Phosphorus. Total Phosphorus was calculated by summing Orthophosphate as P and Phosphorus as P data. Phosphorus as P data were averaged when they were collected on the same day. Five pairs were summed and then averaged for 2007 before comparing with the mean of monthly mean of Total Phosphorus objective. One pair was available for 2006 to compare with the mean of monthly mean of Total Phosphorus objective. The data were not used in cases where only Phosphorus as P was available without Orthophosphate.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | Table 3-14 of the Basin Plan states that the water quality objective for Total P for West Fork Carson River at Woodfords is 0.02 mg/L as a mean of monthly means.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at West Fork Carson River below Willow Creek (633WCR002).
Temporal Representation: | Samples were collected from June 2006 through December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 19993, Phosphorus | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27592
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 3
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | This segment was placed on the Section 303(d) list in 2002 on the basis of calculations by RWQCB staff using data collected by the South Tahoe Public Utility District between 1981 and 2000. The means of monthly means during the assessment period beginning in 1997 were as follows: 1997, 0.09 mg/L; 1998, 0.03 mg/L, 1999, 0.02 mg/L, 2000, 0.03 mg/L.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
| 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The water quality objective for total phosphorus in thiis segment is 0.02 mg/L, expressed as an annual mean of monthly means. This is a running average incorporating historical data.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The South Tahoe PUD data were collected in a diversion ditch upstream of the USGS gage at Woodfords.
Temporal Representation: | The South Tahoe PUD samples were collected approximately monthly between 1981 and 2000.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The South Tahoe Public Utility District maintains its own laboratory and has a quality assurance program acceptable to the RWQCB.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 19993, Phosphorus | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 31691
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 9
Number of Exceedances: | 3
Data and Information Type: | Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: | Three out of nine annual means of monthly means exceeded the water quality objective for total phosphorus expressed as an annual mean of monthly means. A total of 102 samples were collected from the site.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The site specific objective for West Fork Carson River at Woodfords for total phosphorus is 0.02 mg/L as means of monthly means.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at following sampling sites: SW-01 Carson River, W Fork, Crystal Springs Rd.
Temporal Representation: | Samples were collected monthly from January 2002 to June 2010.
Environmental Conditions: |
QAPP Information: | Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 19993, Phosphorus | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27595
Pollutant: | Phosphorus
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled the West Fork Carson River between 2003 and 2005 under the Region 6 SWAMP program. Concentrations of total phosphorus in 10 samples ranged from 0.012 to 0.061 mg/L. Calculated means of monthly means were as follows: 2003, 0.012 mg/L; 2004, 0.018 mg/L, and 2005, 0.022 mg/L.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The water quality objective for total phosphorus in thiis segment is 0.02 mg/L, expressed as an annual mean of monthly means. This is a running average incorporating historical data.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Quarterly samples (3 or 4 per year) were collected between April 2003 and August 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | Sampling and analysis were done according to the SWAMP QAPP. However, in July 2009 an error was discovered in the QAPP related to holding times for total phosphorus samples that affects the validity of data for the Lahontan Region The holding time for samples that are not acid-preserved.should be 48 hours rather than 28 days as indicated in the QAPP. "Low level" phosphorus analyses, without acid preservation, are used in the Lahontan Region's SWAMP program. ..
QAPP Information Reference(s):

DECISION ID | 22458 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Boron
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence, two to evaluate COLD and one to evaluate MUN, are available in the administrative record to assess this pollutant. Samples were collected over a 31 year period between 1980-2010. None of the samples exceeds the California State Notification Level or the site-specific water quality objective. For the 2010 LOE, four samples were estimates and four were below the detection level. The means of monthly means are assumed to be zero values. For the 2012 LOE, three of 32 samples exceeded the boron site specific objective which is 0.02 mg/L as a mean of monthly means. Though the site specific objective is a mean of monthly means, there were few months where more than one sample was collected during the month. As such, the annual average of results from samples collected over a year period was used to determine compliance against the mean of monthly means objective. Over the 31 year period of record between 1 and 12 samples collected over the year were used to calculate the annual average, so some years are more temporally representative of fluctuations in constituent and streamflow conditions. Over the 31 year period of record, 9 or more samples were used to calculate the annual average boron concentration for 25 years. The exceedance associated with the 1980 data was based on one single sample and should not be considered comparitive to an objective that is based on a MOMM. If this exceedance is not considered in the dataset (2010 and 2012 LOES included), there are only 2 exceedances out of 43 total samples and this The three exceedances were measured in 1980, 1985, and 1988. Since 1988, water quality has improved and there have been no exceedances measured during the 22 year period between 1989 and 2010. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 8 samples exceed the MCL for protection of MUN use. Three of 35 samples exceeded the "mean of monthly mean" evaluation criteria. There are three exceedances of 43 samples and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. Though there have been exceedances of boron in this waterbody segment of the West Fork of the Carson River, since 1988, there have been no water quality exceedances measured for the 22 years between 1989 and 2010. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 22458, Boron | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 21501
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 8
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled boron in the West Fork Carson River under the Region 6 SWAMP program. Boron concentrations in 4 of 8 samples were estimates and the remaining 4 samples were below the detection level. The California State Notification Level was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California State Notification Level for boron is 1000 ug/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
| Drinking Water Notification and Response Levels: An Overview
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Eight samples were collected between 2002 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22458, Boron | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4862
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled boron in the West Fork Carson River under the Region 6 SWAMP program. Boron concentrations in 4 of 8 samples were estimates and the remaining 4 samples were below the detection level. Means of monthly means are assumed to be zero. The objective was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective in Lahontan Basin Plan Table 3-14 is 0.02 mg/L (= 20 ug/L) as a mean of monthly means. The objective applies upstream from Woodfords under the Tributary Rule.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Eight samples were collected between 2002 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22458, Boron | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32554
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 31
Number of Exceedances: | 3
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Data were collected over a 31 year period. On 9 of those years, the annual average exceeded 0.02 mg/L.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The site-specific objective in Lahontan Basin Plan Table 3-14 is 0.02 mg/L (= 20 ug/L) as a mean of monthly means. The objective applies upstream from Woodfords under the Tributary Rule.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample collected at the following locations: SW-01-Carson River, W Fork, Crystal Springs Rd D-1-Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 7/8/1980 and 6/2/2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program (by Terry Powers, Laboratory Director). March 30, 2009.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22458, Boron | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32234
Pollutant: | Boron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average of Boron for 2007 for this data set was 0.00383 mg/L which does not exceed the site-specific Water Quality Objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for Boron in the Lahontan Basin Plan page 3-40, states that the mean of monthly mean for Boron shall not exceed 0.02 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data was collected at the following station: 633WCR002 (West Fork Carson River below Willow Creek).
Temporal Representation: | Samples were collected between 8/1/2007 - 11/6/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 21123 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Dissolved oxygen saturation
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. One sample exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the diel, seasonal and annual variations expected in streamflows and dissolved oxygen concentrations in streams of the Lahontan Region. 3. One of 11 samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 21123, Dissolved oxygen saturation | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 44397
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, West Fork (Headwaters to Woodfords) to determine beneficial use support and results are as follows: 1 of 4 samples exceed the criterion for Oxygen, Saturation.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's water quality objective states that the dissolved oxygen concentration shall not be less than 80 percent of saturation.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, West Fork (Headwaters to Woodfords) was collected at 1 monitoring site [ West Fork Carson River below Willow Creek]
Temporal Representation: | Data was collected over the time period 9/13/2007-12/27/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21123, Dissolved oxygen saturation | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 5727
Pollutant: | Dissolved oxygen saturation
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 7
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured dissolved oxygen in the West Fork Carson River under the Region 6 SWAMP program. Percent saturation in 7 quarterly samples taken between February 2004 and August 2005 ranged from 93 to 124 percent. The objective was not violated.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable objective from the Lahontan Basin Plan states: "The dissolved oxygen concentration shall not be depressed by more than 10 percent, below 80 percent saturation, or below 7.0 mg/L at any time, whichever is more restrictive." (Note: this is a watershed-specific narrative objective that differs from the regionwide objectives in Basin Plan Table 3-6.)
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Seven quarterly measurements of percent saturation were taken between February 2004 and August 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 31886 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Electrical Conductivity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence, consisting of 341 samples collected over 31 years, is available in the administrative record to assess this pollutant. None of the 341 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 341 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 31886, Electrical Conductivity | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32198
Pollutant: | Electrical Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 341
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Data were collected over 31 years. Of the 341 samples collected, none measured above 900 uS/cm.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for specific conductance is 900 microsiemens per centimeter (uS/cm).
Objective/Criterion Reference: | Maximum Contaminant Levels for organic and inorganic chemicals. CCR
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample collected at the following locations: SW-01-Carson River, W Fork, Crystal Springs Rd D-1-Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 7/8/1980 and 6/2/2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program (by Terry Powers, Laboratory Director). March 30, 2009.
QAPP Information Reference(s):

DECISION ID | 28292 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Fecal Coliform
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 a single line of evidence is necessary to assess listing status. Six lines of evidence, five to evaluate REC and two to evaluate MUN, are available in the administrative record to assess this pollutant. One of the samples exceed the water quality objective for protection of MUN and Six of 90 samples exceeded the objective of 40 cfu/100 ml for protection of REC. For the 2012 LOE IDs 34863 and 34865 it is more appropriate to evaluate compliance with REC using the 40 cfu/100 ml, and not the 20 cfu/100 ml log mean since only one sample was collected within a 30-day period. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. One of 7 samples exceeded the water quality objective for MUN and 13 of 173 samples exceeded the water quality objective for REC and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 28292, Fecal Coliform | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 34865
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 78
Number of Exceedances: | 7
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Seven of the 78 samples exceeded the Fecal Coliform objective.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml. Water Quality Control Plan for the Lahontan Region.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected at Carson River, W Fork, Crystal Springs Rd.
Temporal Representation: | The samples were collected between January 2004 to June 2010.
Environmental Conditions: |
QAPP Information: | The samples were collected under the South Tahoe Public Utility District Laboratory Quality Assurance Program. Monitoring and Reporting Program NO. R6T-2004-0010.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28292, Fecal Coliform | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 5891
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S. Geological Survey took quarterly samples under the Region 6 SWAMP program between November 2003 and May 2005. Counts of fecal coliform bacteria in seven samples included two samples below the detection level, four estimated values, and one count of 48 colonies per 100 mL. The last sample violated the objective.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for:coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock waste. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected a evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Seven quarterly samples for fecal coliform were taken between November 2003 and May 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28292, Fecal Coliform | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 34863
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Zero of the five samples exceeded the Fecal Coliform objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml. Water Quality Control Plan for the Lahontan Region.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected from station 633WCR002 - West Fork Carson River below Willow Creek.
Temporal Representation: | The samples were collected once a month from August to December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 28292, Fecal Coliform | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 5889
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 7
Number of Exceedances: | 1
Data and Information Type: | Water column surveys (e.g. fecal coliform)
Data Used to Assess Water Quality: | The U.S. Geological Survey took quarterly samples under the Region 6 SWAMP program between November 2003 and May 2005. Counts of fecal coliform bacteria in seven samples included two samples below the detection level, four estimated values, and one count of 48 colonies per 100 mL. The last sample violated the objective.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for coliform bacteria states: "Waters shall not contain concentrations of coliform organisms attributable to anthropogenic sources, including human and livestock waste. The fecal coliform concentration during any 30-day period shall not exceed a log mean of 20/100 ml, nor shall more than 10 percent of all samples collected during any 30-day period exceed 40/100 ml. The log mean shall ideally be based on a minimum of not less than five samples collected a evenly spaced as practicable during any 30-day period. However, a log mean concentration exceeding 20/100 ml for any 30-day period shall indicate violation of this objective even if fewer than five samples were collected."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Seven quarterly samples for fecal coliform were taken between November 2003 and May 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28292, Fecal Coliform | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 31833
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 78
Number of Exceedances: | 5
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Five of the 78 samples exceeded the Fecal Coliform objective.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The fecal coliform concentration shall not exceed more than 40/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected at Carson River, W Fork, Crystal Springs Rd.
Temporal Representation: | The samples were collected between January 2004 to June 2010.
Environmental Conditions: |
QAPP Information: | The samples were collected under the South Tahoe Public Utility District Laboratory Quality Assurance Program. Monitoring and Reporting Program NO. R6T-2004-0010.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28292, Fecal Coliform | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32257
Pollutant: | Fecal Coliform
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Water Contact Recreation
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | Not Specified
Data Used to Assess Water Quality: | Zero of the five samples exceeded the Fecal Coliform objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The fecal coliform concentration shall not exceed more than 40/100 ml.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The samples were collected from station 633WCR002 - West Fork Carson River below Willow Creek.
Temporal Representation: | The samples were collected once a month from August to December 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 31885 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Fluoride
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the two samples exceeded the objective and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 31885, Fluoride | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32267
Pollutant: | Fluoride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Zero of 2 samples exceed the MCL for Flouride.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for Fluoride is 2.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 633WCR002 - West Fork Carson River below Willow Creek.
Temporal Representation: | Samples were collected on the following dates: 8/1/2007 and 11/6/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 32073 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Iron
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence, one to evaluate MUN and one to evaluate COLD, are available in the administrative record to assess this pollutant. None of the two samples exceeds the Iron MCL of 0.3 mg/L for protection of MUN and none of the two samples exceeds the criterion of 1.0 mg/L iron for protection of freshwater aquatic life (COLD). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the two samples exceeds the MCL of 0.3 mg/L Iron for protection of MUN and none of the two samples exceeds the criterion of 1.0 mg/L iron for protection of freshwater aquatic life (COLD), but this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32073, Iron | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 44265
Pollutant: | Iron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, West Fork (Headwaters to Woodfords) to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Iron.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | The Red Book states that based on field observations principally, a criterion of 1.0 mg/L iron for freshwater aquatic life is believed to be adequately protective (National Recommended Water Quality Criteria 2009).
Guideline Reference: | National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Office of Science and Technology
Spatial Representation: | Data for this line of evidence for Carson River, West Fork (Headwaters to Woodfords) was collected at 1 monitoring site [ West Fork Carson River below Willow Creek]
Temporal Representation: | Data was collected over the time period 8/1/2007-11/6/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 32073, Iron | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 44266
Pollutant: | Iron
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, West Fork (Headwaters to Woodfords) to determine beneficial use support and results are as follows: 0 of 2 samples exceed the criterion for Iron.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's Objective for Municipal and Domestic Supply uses of inland surface waters states that waters designated as MUN shall not contain concentrations of chemical constituents in excess of the maximum contaminant level (MCL) or secondary maximum contaminant level (SMCL). This is based upon drinking water standards specified in the following provisions of Title 22 of the California Code of Regulations which are incorporated by reference into the Water Quality Control Plan: Table 64431-A of Section 64431 (Inorganic Chemicals), Table 64431-B of Section 64431 (Fluoride), Table 64444-A of Section 64444 (Organic Chemicals), Table 64449-A of Section 64449 (Secondary Maximum Contaminant Levels-Ranges). The maximum contaminant level listed in Table 64449-A for Iron is 0.3 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, West Fork (Headwaters to Woodfords) was collected at 1 monitoring site [ West Fork Carson River below Willow Creek]
Temporal Representation: | Data was collected over the time period 8/1/2007-11/6/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 28635 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the 44 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 44 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 28635, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27607
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The USGS sampled this station under the Region 6 SWAMP program between 2003 and 2005. Concentrations of nitrite plus nitrate in 10 samples ranged from below the detection level to 0.084 mg/L. The MCL was not exceeded.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite plus nitrate is 10 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Quarterly samples were collected between April 2003 and August 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28635, Nitrate/Nitrite (Nitrite + Nitrate as N) | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 44307
Pollutant: | Nitrate/Nitrite (Nitrite + Nitrate as N)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 34
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, West Fork (Headwaters to Woodfords) to determine beneficial use support and results are as follows: 0 of 34 samples exceed the criterion for Nitrate/Nitrite as N.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Maximum Contaminant Level for nitrate + nitrite (as N) that is incorporated by reference in the Water Quality Control Plan, Lahontan Region is 10.0 mg/L (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, West Fork (Headwaters to Woodfords) was collected at 1 monitoring site [ West Fork Carson River below Willow Creek]
Temporal Representation: | Data was collected over the time period 6/29/2006-12/27/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 28636 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Nitrite
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the 141 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of 141 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 28636, Nitrite | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27606
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The USGS sampled this station under the Region 6 SWAMP program between 2003 and 2005. Four samples for nitrite were all below the detection level. The MCL was not exceeded.
Data Reference: | Administrative Record of Lahontan RWQCB's 2001-2002 Section 303(d) List Update Process Resolution R6T-2002-0002
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for nitrite is 1 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Four samples were collected in April, August, and November 2003 and in August 2004.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | Data meet the quality assurance requirements of the SWAMP QAPP.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28636, Nitrite | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 44327
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 34
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, West Fork (Headwaters to Woodfords) to determine beneficial use support and results are as follows: 0 of 34 samples exceed the criterion for Nitrite as N.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan, Lahontan Basin, Objective for Municipal and Domestic Supply uses of inland surface waters states the following: waters shall not contain concentrations of inorganic chemicals in excess of the limits specified in California Code of Regulations, Title 22, Table 64431-A of section 64431 (Inorganic Chemicals). The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, West Fork (Headwaters to Woodfords) was collected at 1 monitoring site [ West Fork Carson River below Willow Creek]
Temporal Representation: | Data was collected over the time period 6/29/2006-12/27/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 28636, Nitrite | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 31670
Pollutant: | Nitrite
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 103
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: | None of 103 samples exceeded the water quality objective for nitrite.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan, Lahontan Basin, Objective for Municipal and Domestic Supply uses of inland surface waters states the following: waters shall not contain concentrations of inorganic chemicals in excess of the limits specified in California Code of Regulations, Title 22, Table 64431-A of section 64431 (Inorganic Chemicals). The maximum contaminant level listed in Table 64431-A for Nitrite as N is 1.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at SW-01 Carson River, W Fork, Crystal Springs Rd.
Temporal Representation: | Samples were collected from January 2002 to June 2010.
Environmental Conditions: |
QAPP Information: | Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.
QAPP Information Reference(s):

DECISION ID | 21124 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Oxygen, Dissolved
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the secion 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. Two out of 142 of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. Two out of 142 of the samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 21124, Oxygen, Dissolved | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4879
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured dissolved oxygen in the West Fork Carson River under the Region 6 SWAMP program. Dissolved oxygen concentrations in 10 samples ranged from 8 to 12.2 mg/L.. The objective was not violated.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable water quality objective from the Lahontan Basin Plan states: "The dissolved oxygen concentration shall not be depressed by more than 10 percent, below 80 percent saturation, or below 7.0 mg/L at any time, whichever is more restrictive." (Note: this is a watershed-specific narrative objective that differs from the regionwide objectives in Basin Plan Table 3-6.)
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten quarterly dissolved oxygen samples were taken between 2003 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21124, Oxygen, Dissolved | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32558
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 127
Number of Exceedances: | 2
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Data were collected over 31 years. Of the 127 daily averaged samples collected, 2 had dissolved oxygen levels below 7.0 mg/L.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The applicable water quality objective from the Lahontan Basin Plan states: "The dissolved oxygen concentration shall not be depressed by more than 10 percent, below 80 percent saturation, or below 7.0 mg/L at any time, whichever is more restrictive." (Note: this is a watershed-specific narrative objective that differs from the regionwide objectives in Basin Plan Table 3-6.)
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample collected at the following locations: SW-01-Carson River, W Fork, Crystal Springs Rd D-1-Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 7/8/1980 and 6/2/2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program (by Terry Powers, Laboratory Director). March 30, 2009.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21124, Oxygen, Dissolved | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32273
Pollutant: | Oxygen, Dissolved
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 5
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Zero of 5 samples exceeded the water quality objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable site specific water quality objective from p. 3-9 of the Lahontan Basin Plan for the West Fork Carson River Hydrologic Unit states that the dissolved oxygen concentration shall not be below 7.0 mg/L at any time.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 633WCR002 - West Fork Carson River below Willow Creek.
Temporal Representation: | Samples were collected between August and December 2007
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 32112 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Salinity
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the sample (annual average value calculated from 20 samples) exceed the water quality objective. The salinity data provided in this data set is assessed using the site specific objective of 55 mg/L for Total Dissolved Solids at Carson River, West Fork (Headwaters to Woodfords). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the sample exceeded the site specific objective of 55 mg/L TDS and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 26 samples is needed for application of table 3.2. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32112, Salinity | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 34505
Pollutant: | Salinity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average of the 20 samples was 0 mg/L which did not exceed the site specific objective of 55 mg/L.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Regional Board will consider site specific adjustments to the objectives for wetlands (bacteria, pH, hardness, salinity, temperature, or other parameters) as necessary on a case-by-case basis. The site specific objective for Total Dissolved Solids at Carson River, West Fork (Headwaters to Woodfords) is 55 mg/L and will be used to assess the salinity data provided in this data set.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples collected from the 633WCR002 station.
Temporal Representation: | Samples collected approximately twice a month from January 2007 to December 2007
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 32281 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Sodium Adsorption Ratio (SAR)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence are available in the administrative record to assess this pollutant. One of the samples exceeds the water quality objective which is a site specific annual average SAR of 1 mg/L, however this annual average is based on only two samples collected during 2007. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Two samples were used to calculate an annual average and this number of samples is not sufficient to capture the annual and seasonal fluctuations in streamflow and constituent concentrations in this waterbody. 3. One of one samples exceeded the guideline and this sample size is insufficient to determine with the power and confidence of the Listing Policy if standards are not met. A minimum of 16 samples is needed for application of table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32281, Sodium Adsorption Ratio (SAR) | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32276
Pollutant: | Sodium Adsorption Ratio (SAR)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Agricultural Supply
Number of Samples: | 1
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual average for year 2007 was 1.9 and does exceed the water quality objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable site specific water quality objective from the amended Lahontan Basin Plan for the West Fork Carson River states that the annual average SAR (sodium adsorption rate) should not exceed 1.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
| 2006. Amendments to the Water Quality Control Plan for the Lahontan Region: Revised Sodium-Related Standards for the Carson and Walker River Watersheds. Adopted October 12, 2006 under Resolution R6T-2006-0047
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 633WCR002 - West Fork Carson River below Willow Creek.
Temporal Representation: | Data was collected during August 2007 and November 2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 21177 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Specific Conductance
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the 38 samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. 3. None of thirty eight samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 21177, Specific Conductance | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4882
Pollutant: | Specific Conductance
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured specific conductance in the West Fork Carson River under the Region 6 SWAMP program. Ten field measurements ranged from 36 to 80 uS/cm. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for specific conductance is 900 microsiemens per centimeter (uS/cm).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten field measurements were collected between 2003 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21177, Specific Conductance | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 44377
Pollutant: | Specific Conductivity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 28
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, West Fork (Headwaters to Woodfords) to determine beneficial use support and results are as follows: 0 of 28 samples exceed the criterion for Conductivity(Us).
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Secondary MCL that is incorporated by reference in the Water Quality Control Plan, Lahontan Region for specific conductance is 900 uS/cm (Water Quality Control Plan, Lahontan Region).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data for this line of evidence for Carson River, West Fork (Headwaters to Woodfords) was collected at 1 monitoring site [ West Fork Carson River below Willow Creek]
Temporal Representation: | Data was collected over the time period 1/10/2007-12/27/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 21235 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Temperature, water
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None of the 170 samples exceed the water quality objective, which requires establishing baseline conditions. There are sufficient temperature samples, including 20 samples collected between Jan- Dec 2007, to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 170 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. Pertaining to last listing cycle-The Lahontan Basin Plan's narrative temperature objective is an antidegradation-based objective that requires that there be no change in temperature in waters designated for the Cold Freshwater Habitat (COLD) beneficial use. The objective does not include specific numerical limits for protection of the COLD use. Listing Policy Section 3.10 contains directions for assessment based on trends in water quality. These directions include requirements to establish specific baseline conditions and specify the influence of seasonal and interannual effects. Last listing cycle there was only one line of evidence consisting of 10 samples collected quarterly between April 2002 and August 2005. This sampling did not sufficiently capture baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect declining trends in the temperature regime if such trends exist. Because temperature samples were collected only quarterly, weekly and monthly average data are not available for comparison with guidelines in the scientific literature for the temperature requirements of sensitive aquatic species such as salmonids, as directed in Listing Policy Section 6.1.5.9.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 21235, Temperature, water | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 44134
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 20
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Water Board staff assessed SWAMP data for Carson River, West Fork (Headwaters to Woodfords) to determine beneficial use support and results are as follows: 0 of 20 samples exceed the criterion for Water Temperature.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Water Quality Control Plan for the Lahontan Region's water quality objective for all surface waters states the following: The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated COLD, the temperature shall not be altered.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis
Spatial Representation: | Data for this line of evidence for Carson River, West Fork (Headwaters to Woodfords) was collected at 1 monitoring site [ West Fork Carson River below Willow Creek]
Temporal Representation: | Data was collected over the time period 1/10/2007-12/27/2007.
Environmental Conditions: | Staff is not aware of any special conditions that might affect interpretation of the data.
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21235, Temperature, water | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 31700
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 140
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | None of the 140 daily averaged samples exceeded the evaluation guideline for temperature in this water body.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit above or below the natural temperature. For waters designated COLD, the temperature shall not be altered.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: | Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).
Guideline Reference: | Fish introductions in CA: History and impact on native fishes. Davis, CA: University of CA, Davis
Spatial Representation: | Samples were collected at the following locations in this water body: SW-01: Carson River, W Fork, Crystal Springs Rd D-1: Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 7/8/1980 and 6/2/2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program by Terry Powers, Laboratory Director (March 30, 2009)
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21235, Temperature, water | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 5885
Pollutant: | Temperature, water
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled temperature quarterly under the Region 6 SWAMP program between April 2003 and August 2005. Temperature in 10 measurements ranged from 0 to 16.5 degrees Celsius. .
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The temperature objective in the Lahontan Basin Plan states: "The natural receiving water temperature of all waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such an alteration in temperature does not adversely affect the water for beneficial uses. For waters designated WARM, water temperature shall not be altered by more than five degrees Fahrenheit ... above or below the natural temperature. For waters designated COLD, the temperature shall not be altered. Temperature objectives for COLD interstate waters and WARM interstate waters are as specified in the 'Water Quality Control Plan for Control of Temperature in The Coastal and Interstate Waters and Enclosed Bays and Estuaries of California' including any revisions."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten quarterly water temperature measurements were taken between April 2003 and August 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 22578 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | pH
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant, however, the 2010 line of evidence was not used since the ambient pH level of the waterbody was not known. The 2012 LOE contains 342 samples collected over a 15 year period. Though we could make a safe assumption that none of these samples exceed the water quality objective, no trend analysis has been done to determine ambient baseline conditions as of yet. There are sufficient temperature to establish baseline conditions (including diel, seasonal, annual and interannual variations in temperature) or to detect trends in pH if such trends exist. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Based on a decision entry by State Board staff NM on Dec. 19, 2013, none of 342 samples exceeded the objective, and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. Regional Board staff, however, recognize that the dataset needs to be analyzed to establish baseline conditions (normal ambient pH) for this waterbody to determine with certainty that this waterbody supports COLD. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 22578, pH | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32538
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 342
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | There were 342 samples with daily average pH ranging from 5.97 to 9.71.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The applicable objective states: "Changes in normal ambient pH levels shall not exceed 0.5 unit." This is a watershed-specific objective, different from the Lahontan Basin Plan's regionwide objective .
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample collected at the following locations: SW-01-Carson River, W Fork, Crystal Springs Rd D-1-Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 11/1/1995 and 6/2/2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program (by Terry Powers, Laboratory Director). March 30, 2009.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22578, pH | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4881
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey measured pH in the West Fork Carson River under the Region 6 SWAMP program. The pH values in 10 samples collected from 2003 to 2005 ranged from 6.9 to 7.9 units.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable objective states: "Changes in normal ambient pH levels shall not exceed 0.5 unit." This is a watershed-specific objective, different from the Lahontan Basin Plan's regionwide objective .
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten pH measurements were taken between 2003 and 2005. .
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 22578, pH | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32260
Pollutant: | pH
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 0
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | There were 20 samples with pH ranging from 6.9 to 8.6. The normal ambient pH level for this water body is unknown and so it is unknown whether any exceedences occured.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The applicable objective states: "In fresh waters with designated beneficial uses of COLD or WARM, changes in normal ambient pH levels shall not exceed 0.5 pH units." (Lahontan Basin Plan).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at Station 633WCR002 - West Fork Carson River below Willow Creek.
Temporal Representation: | Samples were collected between 1/10/2007 and 12/27/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

DECISION ID | 21074 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Chloride
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2025
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence, three to evaluate COLD and one to evaluate MUN, are available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective (MCL) for protection of MUN. The site-specific water quality objective, expressed as a "mean of monthly means" is used to evaluate compliance with COLD. Twenty six exceedances occurred over 35 annual time periods. Though the site specific objective is a mean of monthly means, there were few months were more than one sample was collected during the month. As such the annual average of results from samples collected over a year period was used to determine compliance against the mean of monthly means objective. Over the 30 year period of record between 1 and 14 samples collected over the year were used to calculate the annual average, so some years are more temporally representative of fluctuations in constituent and streamflow conditions. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy; however, annual averages were compared to the COLD site specific objective to determine compliance. 3. Twenty six of 35 annual mean of monthly means datapoints exceed the site specific objective, and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

Line of Evidence (LOE) for Decision ID 21074, Chloride | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4866
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled chloride in the West Fork Carson River under the Region 6 SWAMP program. Chloride concentrations in 10 samples ranged from 0.54 to 3.02 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for chloride is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten samples were collected between 2002 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21074, Chloride | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4864
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 3
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled chloride in the West Fork Carson River under the Region 6 SWAMP program. Chloride concentrations in 10 samples ranged from 0.54 to 3.02 mg/L. The mean of monthly means objective, calculated beginning in 2003, was exceeded in 3 of 3 years.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective in Lahontan Basin Plan Table 3-14 is 1.0 mg/L as a mean of monthly means. The objective applies upstream from Woodfords under the Tributary Rule.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten samples were collected between 2002 and 2005. Means of monthly means were calculated for each of three years.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 21074, Chloride | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32241
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The mean of monthly means of chloride data for year 2006 does not exceed the Water Quality Objective. The mean of monthly means of chloride data for year 2007 does exceed the Water Quality Objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for Chloride in the Lahontan Basin Plan page 3-40, states that the mean of monthly means for Chloride shall not exceed 1.0 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 633WCR002 - West Fork Carson River below Willow Creek.
Temporal Representation: | Samples were collected 6/29/2006 - 12/7/2006 and 1/10/2007 - 12/27/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 21074, Chloride | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32539
Pollutant: | Chloride
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 30
Number of Exceedances: | 22
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Data were collected for 30 years between 1980 and 2010 (no data were collected in 1982). For those 30 years, the annual average exceeded 1.0 mg/L on 22 of the years.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The site-specific objective in Lahontan Basin Plan Table 3-14 is 1.0 mg/L as a mean of monthly means. The objective applies upstream from Woodfords under the Tributary Rule.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample collected at the following locations: SW-01-Carson River, W Fork, Crystal Springs Rd D-1-Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 1980 and 2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program (by Terry Powers, Laboratory Director). March 30, 2009.
QAPP Information Reference(s):

DECISION ID | 28445 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Sulfates
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2025
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence, three to evaluate COLD and one to evaluate MUN, are available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level for protection of MUN. Twenty two of the "mean of monthly means" datapoinits exceed the site-specific water quality objective of 2 mg/L (applied upstream through the Tributary Rule from the West Fork Carson River at Woodfords station). Four annual averages associated with the 2012 LOE (32555) were not considered as exceedances because the detection limit for sulfate for years 1983-1986 was above the site specific objective. Though the site specific objective is a mean of monthly means, there were few months were more than one sample was collected during the month. As such, the annual average of results from samples collected over a year period was used to determine compliance against the mean of monthly means objective. Over the 28 year period of record for 2012 LOE 32555 between 1 and 13 samples collected over the year were used to calculate the annual average, so some years are more temporally representative of fluctuations in constituent and streamflow conditions. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy; however annual averages were used to determine compliance against a MOMM site specific objective. 3. None of 10 samples exceeded the California Maximum Contaminant Level. Twenty six of 33 "mean of monthly means" datapoints exceeded the site-specific objective and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

Line of Evidence (LOE) for Decision ID 28445, Sulfates | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4884
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 3
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled the West Fork Carson River under the Region 6 SWAMP program between 2003 and 2005. Sulfate concentrations in 10 samples ranged from 0.8 to 3.8 mg/L. The annual mean of monthly means, calculated for each year from 2003 to 2005, exceeded the objective in each year (the highest value was 2.44 mg/L in 2003).
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for sulfate is 2.0 mg/L as a mean of monthly means (applied upstream through the Tributary Rule from the West Fork Carson River at Woodfords station). See Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten quarterly samples were collected between 2003 and 2005 and means of monthly means were computed for three years.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28445, Sulfates | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4885
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled suspended sediment in the West Fork Carson River under the Region 6 SWAMP program. Sulfate concentrations in 10 samples ranged from 0.8 to 3.8 mg/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for sulfate is 250 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten samples were collected between 2003 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28445, Sulfates | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32264
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 1
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The sample collected for year 2006 did not exceed the water quality objective. The sample collected for year 2007 did exceed the water quality objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | From the Lahontan Basin Plan Table 3-14, the water quality objective for sulfate in this water body is a mean of monthly means of 2 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample was collected at station 633WCR002 - West Fork Carson River below Willow Creek.
Temporal Representation: | The samples were collected 6/29/2006 - 12/7/2006 and 1/10/2007 - 12/27/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 28445, Sulfates | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32555
Pollutant: | Sulfates
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 28
Number of Exceedances: | 22
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Data were collected over a 28 year period. On 22 of those years, the annual average exceeded 2.0 mg/L. Exceedances for years 1983-1986 were not considered since the detection limit was above the site-specific objective.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The site-specific objective for sulfate is 2.0 mg/L as a mean of monthly means (applied upstream through the Tributary Rule from the West Fork Carson River at Woodfords station). See Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample collected at the following locations: SW-01-Carson River, W Fork, Crystal Springs Rd D-1-Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 9/12/1983 and 6/2/2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program (by Terry Powers, Laboratory Director). March 30, 2009.
QAPP Information Reference(s):

DECISION ID | 28464 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Total Dissolved Solids
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2025
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Four lines of evidence, three to evaluate COLD and one to evaluate MUN, are available in the administrative record to assess this pollutant. None of the samples exceeds the California Maximum Contaminant Level. Nine of the 36 samples exceed the water quality objective, which is a site-specific objective of 55 mg/L as a mean of monthly means (applied upstream through the Tributary Rule from the West Fork Carson River at Woodfords station). Though the site specific objective is a mean of monthly means, there were few months were more than one sample was collected during the month. As such, the annual average of results from samples collected over a year period was used to determine compliance against the mean of monthly means objective. Over the 31 year period of record between 1 and 12 samples collected over the year were used to calculate the annual average, so some years are more temporally representative of fluctuations in constituent and streamflow conditions. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used does satisfy the data quantity requirements of section 6.1.5 of the Policy; however, annual averages were compared to a MOMM site specific objective to determine compliance. 3. None of 10 samples exceeds the MCL for protection of MUN and nine of the 36 samples exceed the mean of monthly means and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

Line of Evidence (LOE) for Decision ID 28464, Total Dissolved Solids | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32228
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The annual averages for TDS for both years for this data set were below the Water Quality Objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-pecific objective for Total Dissolved Solids (TDS) in Lahontan Basin Plan Table 3-14, includes an annual average of 55 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 633WCR002 (West Fork Carson River below Willow Creek).
Temporal Representation: | Samples were collected between 6/29/2006 - 12/7/2006 and 1/10/2007 - 11/6/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 28464, Total Dissolved Solids | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32557
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 31
Number of Exceedances: | 8
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Data were collected over 31 years. For eight of those years, the annual average exceeded 55 mg/L.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The site-specific objective for total dissolved solids (TDS) is 55 mg/L as a mean of monthly means (applied upstream through the Tributary Rule from the West Fork Carson River at Woodfords station). See Lahontan Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample collected at the following locations: SW-01-Carson River, W Fork, Crystal Springs Rd D-1-Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 7/8/1980 and 6/2/2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program (by Terry Powers, Laboratory Director). March 30, 2009.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28464, Total Dissolved Solids | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4886
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled TDS in the West Fork Carson River under the Region 6 SWAMP program. TDS concentrations in 10 quarterly samples collected between 2003 and 2005 ranged from 35 to 71 mg/L. The MCL was not violated.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for Total Dissolved Solids is 500 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten quarterly samples were collected between 2002 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28464, Total Dissolved Solids | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4887
Pollutant: | Total Dissolved Solids
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 3
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled chloride in the West Fork Carson River under the Region 6 SWAMP program. TDS concentrations in 10 samples ranged from 35 to 71 mg/L. The annual mean of monthly means, calculated for each year from 2003 to 2005, exceeded the objective in one out of 3 years (the highest value was 57.5 mg/L in 2004).
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for total dissolved solids (TDS) is 55 mg/L as a mean of monthly means (applied upstream through the Tributary Rule from the West Fork Carson River at Woodfords station). See Lahontan Basin Plan Table 3-14.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten samples were collected between 2002 and 2005. Annual means of monthly means were calculated for a three year period.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 28456 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Turbidity
Final Listing Decision: | List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Revised
Sources: | Source Unknown
Expected TMDL Completion Date: | 2025
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Six lines of evidence, four to evaluate protection of COLD and two to evaluate protection of MUN, are available in the administrative record to assess this pollutant. Two of the samples expressed as NTU exceed the California Maximum Contaminant Level for protection of MUN. For the LOEs to evaluate COLD, the 2010 LOE (21502) was based on turbidity expressed as NTRU and since there are no applicable standards or criteria for turbidity expressed as NTRU this data should not be considered in the final use rating. Eight of 34 samples exceeded the narrative water quality objective used to assess the COLD, which is antidegradation- based and is based on a MOMM site specific objective of 2NTUs. Though the site specific objective is a mean of monthly means, there were few months were more than one sample was collected during the month. As such, the annual average of results from samples collected over a year period was used to determine compliance against the mean of monthly means objective. Over the 30 year period of record for 2012 LOE (32556) between 1 and 12 samples collected over the year were used to calculate the annual average, so some years are more temporally representative of fluctuations in constituent and streamflow conditions. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfy the data quantity requirements of section 6.1.5 of the Policy; however, annual averages were compared to MOMM site specific objective to determine compliance. 3. Two of 6 samples exceeded the California Maximum Contaminant Level for protection of MUN and eight of 34 samples (LOE 21502 is not included) exceeded the turbidity objective (mean of monthly means) for protection of COLD. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

Line of Evidence (LOE) for Decision ID 28456, Turbidity | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4888
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 2
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled this station under of the Region 6 SWAMP program.between 2003 and 2004. Two of 6 field turbidity measurements expressed as NTU were below the detection level. The other samples ranged from 2 to 31 NTU. With calculations counting the estimated values as zeros, the means of monthly means were 1.3 NTU for 2003 and 7.0 NTU for 2004.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for turbidity states: "The turbidity shall not be raised above a mean of monthly means value of 2 NTU. (This objective is approximately equal to the State of Nevada standard of 2 NTU annual mean)." This is a watershed-specific objective that differs from the regionwide narrative objective.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Six field turbidity measurements expressed as NTU were taken in 2003 and 2004.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28456, Turbidity | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 21503
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 6
Number of Exceedances: | 2
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled this station under of the Region 6 SWAMP program.between 2003 and 2004. Two of 6 field turbidity measurements expressed as NTU were below the detection level. The other samples ranged from 2 to 31 NTU. Two samples exceeded the MCL.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The MCL for turbidity is 5 NTU.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Six field turbidity measurements expressed as NTU were taken in 2003 and 2004.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28456, Turbidity | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 21504
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled this station under of the Region 6 SWAMP program.between 2004 and 2005. Three of 4 field turbidity measurements expressed as NTRU were below the detection level. The fourth sample had a turbidity of 8.4 NTRU.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards or criteria for turbidity expressed as NTRU for the protection of human health.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Four field turbidity measurements expressed as NTRU were taken in 2004 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28456, Turbidity | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32231
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | The mean of monthly means for turbidity for 2007 for this data set was below the site-specific Water Quality Objective.
Data Reference: | RWB6 Trend Monitoring CY2006 CY2007
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The site-specific objective for Turbidity (NTU) in Lahontan Basin Plan page 3-10, states that turbidity shall not be raised above a mean of monthly means value of 2 NTU.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Data were collected at the following station: 633WCR002 (West Fork Carson River below Willow Creek).
Temporal Representation: | Samples were collected between 1/10/2007 - 12/27/2007.
Environmental Conditions: |
QAPP Information: | 2002 QAMP (Quality Assurance Management Plan) for the State of California's Surface Water Ambient Monitoring Program
QAPP Information Reference(s): | Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)
Line of Evidence (LOE) for Decision ID 28456, Turbidity | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 21502
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled this station under of the Region 6 SWAMP program.between 2004 and 2005. Three of 4 field turbidity measurements expressed as NTRU were below the detection level. The fourth sample had a turbidity of 8.4 NTRU.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no state or federal standards or criteria for turbidity expressed as NTRU for the protection of aquatic life.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Four field turbidity measurements expressed as NTRU were taken in 2004 and 2005.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28456, Turbidity | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 32556
Pollutant: | Turbidity
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 31
Number of Exceedances: | 7
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING
Data Used to Assess Water Quality: | Data were collected over 31 years. For seven of those years, the annual average exceeded 2 NTU.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan's objective for turbidity states: "The turbidity shall not be raised above a mean of monthly means value of 2 NTU. (This objective is approximately equal to the State of Nevada standard of 2 NTU annual mean)." This is a watershed-specific objective that differs from the regionwide narrative objective.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Sample collected at the following locations: SW-01-Carson River, W Fork, Crystal Springs Rd D-1-Carson River, West Fork @ Diversion
Temporal Representation: | Samples collected between 7/8/1980 and 6/2/2010.
Environmental Conditions: |
QAPP Information: | South Tahoe Public Utility District Laboratory Quality Assurance Program (by Terry Powers, Laboratory Director). March 30, 2009.
QAPP Information Reference(s):

DECISION ID | 30066 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Sodium
Final Listing Decision: | Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Delist from 303(d) list (TMDL required list)(2010)
Revision Status | Original
Reason for Delisting: | Other
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for removal on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This segment was placed on the 2002 Section 303(d) list for violation of the water quality objective for "Percent Sodium." Percent Sodium is the ratio of sodium ion concentration to the sum of the concentrations of calcium, magnesium and potassium ions. It is an older irrigation water criterion and is no longer widely used.The 2002 listing was for "Sodium" rather than "Percent Sodium" because "Sodium" was the only picklist choice available in the database in use at the time. In 2006 the Lahontan RWQCB adopted Basin Plan amendments to replace the water quality objectives for percent sodium for surface waters of the Carson and Walker River watersheds with new objectives for "Sodium Adsorption Ratio" (SAR). The amendments were approved by the SWRCB and the Office of Administrative Law in 2007 and by the USEPA, Region IX in 2008. . SAR is a ratio of sodium ion concentration to the concentrations of calcium and magnesium ions. It is calculated differently from Percent Sodium and the two types of objectives are NOT directly comparable. The SAR limits in the new objectives are compatible with current federal and international irrigation water quality criteria and with the State of Nevada's antidegradation- based SAR standards for state line stations. The new SAR limits are expressed as annual means, rather than means of monthly means. A single SAR objective for the West Fork Carson River in California has replaced the two objectives for Percent Sodium that were applicable to different segments of the river. The listing for sodium is being considered for removal from the section 303(d) list under section 4 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. The new SAR objective for the Headwaters to Woodfords segment of the West Fork Carson River has been attained in 19 out of 19 years. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1.The data used satisfy the data quality requirements of section 6.1.4 of the Listing Policy. 2. The data used satisfy the data quantity requirements of section 6.1.4 of the Listing Policy. 3. The new water quality objective was attained in 19 out of 19 years and this does not exceed the allowable frequency in Table 3.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle. RWQCB staff concludes that the water body-pollutant combination should be removed from the Section 303(d) list because Basin Plan amendments deleting and replacing the water quality objective involved in the 2002 listing have been approved and are in effect and the applicable water quality standards for the pollutant are not being exceeded.

Line of Evidence (LOE) for Decision ID 30066, Sodium | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 5375
Pollutant: | Sodium
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Agricultural Supply
Number of Samples: | 19
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | Table 3 of the Region 6 staff report for the Basin Plan amendments summarizes annual average SAR values for the West Fork Carson River. Lahontan RWQCB staff calculated these averages using historical data on SAR or the component ions. For data collected by the South Tahoe Public Utility District between 1984 and 2002, annual average SAR values ranged from 0.2 to 0.3. The mean annual average value was 0.3. The water quality objective (SAR =1) was attained.
Data Reference: | Self-monitoring monthly reports from 2000 to 2003. Including Carson River and Indian Creek
| Self-monitoring monthly reports from 1997 to 2000. Including Carson River and Indian Creek
| Memorandum: Summary of water quality analysis for potential CWA 303(d) listing of the lower West Fork of the Carson River. South Lake Tahoe, CA: Lahontan RWQCB
| 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
| 2006. Technical Staff Report for Revised Sodium-Related Standards for the Carson and Walker River Watersheds
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The water quality objective for Sodium Adsorption Ratio (SAR) in the West Fork Carson River is a limit of 1, as an annual average. (As a ratio, SAR has no units.) The objective includes the formula for calculating SAR and natural sources exclusion language. The approved plan amendments have not yet been physically incorporated into the text of the Basin Plan. A copy of the amendments is included in the administrative record of the 2008 Integrated Report and is used as a reference in this LOE.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
| 2006. Amendments to the Water Quality Control Plan for the Lahontan Region: Revised Sodium-Related Standards for the Carson and Walker River Watersheds. Adopted October 12, 2006 under Resolution R6T-2006-0047
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | The data were collected in a canal diverting water from the West Fork Carson River upstream of the USGS gage at Woodfords.
Temporal Representation: | The data cited above were collected at approximately monthly intervals between 1984 and 2002, for 224 samples in all. Nineteen annual average calculations were done.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley. It joins the East Fork to form the Carson River in Nevada. Water from the West Fork is used for irrigation of pasture and some field crops in the Carson Valley in California, and it contributes to the irrigation supply in Nevada.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 28290 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | 2, 6- diethylaniline | 2-chloro-4-isopropylamino-6-amino-s-triazine | Alachlor | Atrazine | Azinphos-methyl (Guthion) | Benefin | Butylate | Carbaryl | Carbofuran | Chlorpyrifos | Cyanazine | DDE (Dichlorodiphenyldichloroethylene) | Dacthal | Diazinon | Dieldrin | Disulfoton | Dyfonate (Fonofos or Fonophos) | EPTC (Eptam, s-ethyl dipropylthiocarbamate) | Ethalfluralin | Ethoprop | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Linuron | Malathion | Methyl Parathion | Metolachlor | Metribuzin | Molinate | Napropamide | Parathion | Pendimethalin | Permethrin, total | Phorate | Prometon (Prometone) | Pronamide | Propachlor | Propanil (DCPA mono- and di-acid degrad) | Propargite | Simazine | Tebuthuron | Terbacil | Terbufos | Thiobencarb/Bolero | Triallate | Trifluralin
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: These pollutants are being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. Samples were analyzed for 46 pesticides, and 45 of these were not detected. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not the data quantity requirements of section 6.1.5 of the Policy. Samples were collected during four consecutive months and did not represent seasonal and annual variation. Sampling was done in 1994 and is not necessarily representative of current conditions in the watershed. 3. Four samples were analyzed for 46 pesticides; 45 of these were not detectable. Under the Section 6.1.5.5 of the Listing Policy, applicable standards and criteria for the nondetectable pesticides are considered to be attained. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 28290, Multiple Pollutants | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 26739
Pollutant: | 2, 6- diethylaniline | 2-chloro-4-isopropylamino-6-amino-s-triazine | Alachlor | Atrazine | Azinphos-methyl (Guthion) | Benefin | Butylate | Carbaryl | Carbofuran | Chlorpyrifos | Cyanazine | DDE (Dichlorodiphenyldichloroethylene) | Dacthal | Diazinon | Dieldrin | Disulfoton | Dyfonate (Fonofos or Fonophos) | EPTC (Eptam, s-ethyl dipropylthiocarbamate) | Ethalfluralin | Ethoprop | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Linuron | Malathion | Methyl Parathion | Metolachlor | Metribuzin | Molinate | Napropamide | Parathion | Pendimethalin | Permethrin, total | Phorate | Prometon (Prometone) | Pronamide | Propachlor | Propanil (DCPA mono- and di-acid degrad) | Propargite | Simazine | Tebuthuron | Terbacil | Terbufos | Thiobencarb/Bolero | Triallate | Trifluralin
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The California Department of Pesticide Regulation's online database includes data for the West Fork Carson River at Woodfords. These data were collected in May, June, July and August 1994 as part of the U.S. Geological Survey's National Water Quality Assessment (NAWQA) program.. Only one of the 46 listed pesticides (pebulate) was detected, in one of four samples. The concentration was reported as 0.0090 ug/L.
Data Reference: | Department of Pesticide Regulation Database Records for the West Fork Carson River and Upper Truckee Rivers
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | Documentation of water quality criteria for individual pollutants in Lines of Evidence for multipollutant datasets is not required, except for pollutants that exceed a standard or criterion. There are no state or federal water quality standards or criteria for pebulate, the only detectable pollutant in this dataset. The Lahontan Basin Plan includes a narrative water quality objective for pesticides in surface waters that provides that: "Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable leves, using the most recent detection procedures available."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River at Woodfords, was sampled.
Temporal Representation: | Samples were collected on May 10, June 13, July 12, and August 8, 1994 and analyzed for the 46 listed pesticides.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use. The Woodfords station was sampled as part of the USGS National Water Quality Assessment (NAWQA) study of the Carson River watershed in California and Nevada, as part of a larger study of the Truckee and Carson Rivers and Las Vegas Wash.. Woodfords is upstream of the portion of the watershed used for irrigated agriculture.
QAPP Information: | The data meet USGS quality assurance requirements.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28290, Multiple Pollutants | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 26846
Pollutant: | 2, 6- diethylaniline | 2-chloro-4-isopropylamino-6-amino-s-triazine | Alachlor | Atrazine | Azinphos-methyl (Guthion) | Benefin | Butylate | Carbaryl | Carbofuran | Chlorpyrifos | Cyanazine | DDE (Dichlorodiphenyldichloroethylene) | Dacthal | Diazinon | Dieldrin | Disulfoton | Dyfonate (Fonofos or Fonophos) | EPTC (Eptam, s-ethyl dipropylthiocarbamate) | Ethalfluralin | Ethoprop | Hexachlorobenzene/ HCB | Lindane/gamma Hexachlorocyclohexane (gamma-HCH) | Linuron | Malathion | Methyl Parathion | Metolachlor | Metribuzin | Molinate | Napropamide | Parathion | Pendimethalin | Permethrin, total | Phorate | Prometon (Prometone) | Pronamide | Propachlor | Propanil (DCPA mono- and di-acid degrad) | Propargite | Simazine | Tebuthuron | Terbacil | Terbufos | Thiobencarb/Bolero | Triallate | Trifluralin
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 4
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The California Department of Pesticide Regulation's online database includes data for the West Fork Carson River at Woodfords. These data were collected in May, June, July and August 1994 as part of the U.S. Geological Survey's National Water Quality Assessment (NAWQA) program.. Only one of the 46 listed pesticides (pebulate) was detected, in one of four samples. The concentration was reported as 0.0090 ug/L.
Data Reference: | Department of Pesticide Regulation Database Records for the West Fork Carson River and Upper Truckee Rivers
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | Documentation of water quality criteria for individual pollutants in Lines of Evidence for multipollutant datasets is not required, except for pollutants that exceed a standard or criterion. There are no state or federal water quality standards or criteria for pebulate, the only detectable pollutant in this dataset. The Lahontan Basin Plan includes a narrative water quality objective for pesticides in surface waters that provides that: "Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable leves, using the most recent detection procedures available." For waters designated for the Municipal and Domestic Supply beneficial use, the water quality objective references the California Maximum Contaminant Levels (MCLs) for pesticides.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River at Woodfords, was sampled.
Temporal Representation: | Samples were collected on May 10, June 13, July 12, and August 8, 1994 and analyzed for the 46 listed pesticides.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use. The Woodfords station was sampled as part of the USGS National Water Quality Assessment (NAWQA) study of the Carson River watershed in California and Nevada, as part of a larger study of the Truckee and Carson Rivers and Las Vegas Wash.. Woodfords is upstream of the portion of the watershed used for irrigated agriculture.
QAPP Information: | The data meet USGS quality assurance requirements.
QAPP Information Reference(s):

DECISION ID | 20767 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Arsenic
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. The single sample did not exceed the California Toxics Rule aquatic life standards or the California Maximum Contaminant Level. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The single sample used does not satisfy the data quantity requirements of section 6.1.5 or Table 3.1 of the Policy. 3. The single sample does not exceed either of the applicable standards and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 20767, Arsenic | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4861
Pollutant: | Arsenic
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled arsenic in the West Fork Carson River under the Region 6 SWAMP program. One sample had an arsenic concentration of 0.6 ug/L. The California Toxics Rule standards were not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The California Toxics Rule standards for protection of freshwater aquatic life are: 4-day average = 150 ug/L 1-hour average = 340 ug/L
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | One sample was collected on 11/24/2004..
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 20767, Arsenic | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4860
Pollutant: | Arsenic
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Dissolved
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 1
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled arsenic in the West Fork Carson River under the Region 6 SWAMP program. One sample had an arsenic concentration of 0.6 ug/L. The MCL was not exceeded.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | California Maximum Contaminant Levels apply to ambient waters under the Lahontan Basin Plan's "Chemical Constituents" objective. The state MCL for arsenic is 10 ug/L (effective November 28, 2008).
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | One sample was collected on 11/24/2004.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):

DECISION ID | 32074 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Nitrogen, ammonia (Total Ammonia)
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | New Decision
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the 97 samples exceed the water quality objective, which for unionized ammonia in waters with salmonids present requires sample concentrations to fall within the 4-day chronic criteria range of 0.0011 mg/L to 0.033 mg/L. . Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 97 samples exceeded the objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because applicable water quality standards are not being exceeded.

Line of Evidence (LOE) for Decision ID 32074, Nitrogen, ammonia (Total Ammonia) | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 31671
Pollutant: | Nitrogen, ammonia (Total Ammonia)
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Total
Beneficial Use: | Fish Spawning
Number of Samples: | 97
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical monitoring (conventional pollutants only)
Data Used to Assess Water Quality: | None of 97 samples exceeded the water quality objective for unionized ammonia. Data were reported as as total ammonia as nitrogen and were converted to unionized ammonia before being compared with the objective. Some samples had temperature or pH values outside the range of the criteria and were not counted.
Data Reference: | Data for temperature, nutrients, and bacteria in Heavenly Valley Creek (USFS boundary to Trout Creek) and various water bodies in Alpine County, Jul 1980-Jun. 2010
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | The Lahontan Basin Plan objective for unionized ammonia is a function of pH, temperature, and the presence of salmonids. The 4-day chronic criteria for unionized ammonia with salmonids present ranged from 0.0011 mg/L to 0.033 mg/L.
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | Samples were collected at SW-01 Carson River, W Fork, Crystal Springs Rd.
Temporal Representation: | Samples were collected from January 2002 to June 2010.
Environmental Conditions: |
QAPP Information: | Samples were collected by STPUD and analyzed using STPUD Laboratory quality assurance program.
QAPP Information Reference(s):

DECISION ID | 28340 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Pebulate
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. One of the samples exceeds the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Samples were collected only in the spring and summer. 3. One of four samples exceeded the water quality objective and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 28340, Pebulate | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27045
Pollutant: | Pebulate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 4
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The California Department of Pesticide Regulation database contains data from the USGS National Water Quality Assessment (NAWQA) program. Four samples were collected in May, June, July and August 1994. Pebulate was detected in one sample collected June 13, 1994, at a concentration of 0.0090 ug/L.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | There are no specific state or federal standards or criteria for pebulate. The Lahontan Basin Plan includes a narrative water quality objective for pesticides in surface waters that provides that: "Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable leves, using the most recent detection procedures available."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Samples were collected in May, June, July an August 1994.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | USGS quality assurance procedures were used.
QAPP Information Reference(s):
Line of Evidence (LOE) for Decision ID 28340, Pebulate | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 27046
Pollutant: | Pebulate
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | Not Recorded
Beneficial Use: | Municipal & Domestic Supply
Number of Samples: | 4
Number of Exceedances: | 1
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The California Department of Pesticide Regulation database contains data from the USGS National Water Quality Assessment (NAWQA) program. Four samples were collected in May, June, July and August 1994. Pebulate was detected in one sample collected June 13, 1994, at a concentration of 0.0090 ug/L.
Data Reference: | Department of Pesticide Regulation Database Records for the West Fork Carson River and Upper Truckee Rivers
SWAMP Data: | Non-SWAMP
Water Quality Objective/Criterion: | There are no specific state or federal standards or criteria for pebulate. The Lahontan Basin Plan includes a narrative water quality objective for pesticides in surface waters that provides that: "Pesticide concentrations, individually or collectively, shall not exceed the lowest detectable leves, using the most recent detection procedures available."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Samples were collected in May, June, July an August 1994.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters. In addition to the Cold Freshwater Habitat beneficial use, the West Fork Carson River is designated for the Spawning, Reproduction, and Development Use.
QAPP Information: | USGS quality assurance procedures were used.
QAPP Information Reference(s):

DECISION ID | 21802 | Region 6
Carson River, West Fork (Headwaters to Woodfords)

Pollutant: | Sediment
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2010)
Revision Status | Original
Impairment from Pollutant or Pollution: | Pollutant
Regional Board Staff Conclusion: | Regional Board conclusion: This pollutant was considered for placement on the section 303(d) list in a previous assessment cycle.No new information ws reviewed for this current assessment cycle. Therefore, the previous conclusion remains unchanged, and is as follows: The Lahontan Basin Plan's narrative water quality objective is an antidegradation based objective that provides that there shall be no increases in suspended sediment concentrations or loads. This pollutant is being considered for placement on the section 303(d) list under section 3.10 of the Listing Policy, which deals with trends in water quality. One line of evidence, based on quarterly sampling, is available in the administrative record to assess this pollutant. It includes 10 suspended sediment concentration values and 8 suspended sediment load values calculated from instantaneous discharge measurements. Suspended sediment concentrations and loads are dependent on flows and can change rapidly over a short time during storm or snowmelt runoff events. Quarterly samples are insufficient to capture these short term events and therefore are insufficient to define natural background suspended sediment concentrations and loads, or to detect trends. Listing Policy Section 3.10 requires that natural background conditions be established. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfy the data quality requirements of section 6.1.4 of the Policy. 2. The data used do not satisfy the data quantity requirements of section 6.1.5 of the Policy. Quarterly samples do not capture the diel, seasonal and annual variability expected in streamflows and suspended sediment concentrations in the Lahontan Region. 2. Sampling frequency was insufficient to establish natural background conditions and therefore does not meet the requirements of Listing Policy Section 3.10. 3. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.
Regional Board Staff Decision Recommendation: | No new data were assessed for this assessment cycle. The conclusion reached in the previous cycle remains the same. The Regional Board will update this decision when new data and information become available in a future assessment cycle.

Line of Evidence (LOE) for Decision ID 21802, Sediment | Region 6
Carson River, West Fork (Headwaters to Woodfords)
LOE ID: | 4883
Pollutant: | Sediment
LOE Subgroup: | Pollutant-Water
Matrix: | Water
Fraction: | None
Beneficial Use: | Cold Freshwater Habitat
Number of Samples: | 10
Number of Exceedances: | 0
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants)
Data Used to Assess Water Quality: | The U.S. Geological Survey sampled suspended sediment in the West Fork Carson River under the Region 6 SWAMP program and calculated sediment loads with concurrent flow data. Instantaneous discharge flows ranged from 7.3 to 549 cfs. The highest flow was measured during spring runoff season in May 2005. Suspended sediment concentrations in 10 samples ranged from 1 to 32 mg/L. Suspended sediment loads in 8 calculations ranged from 0.06 to 47 tons per day.
Data Reference: | 2007. SWAMP Data for the East Fork and West Fork Carson River Hydrologic Units
SWAMP Data: | SWAMP
Water Quality Objective/Criterion: | The objective in the Lahontan Basin Plan states: "The suspended sediment load and suspended sediment discharge rate of surface waters shall not be altered in such a manner as to cause nuisance or adversely affect the water for beneficial uses."
Objective/Criterion Reference: | Water Quality Control Plan for the Lahontan Region (as amended)
Evaluation Guideline: |
Guideline Reference:
Spatial Representation: | One station, West Fork Carson River below Willow Creek, was sampled.
Temporal Representation: | Ten samples were collected between 2003 and 2005 and 8 loading calculations were done.
Environmental Conditions: | The West Fork Carson River is an interstate river with headwaters near the Sierra Nevada crest and its lowest point in California in the Carson Valley, transitional between Sierra and Great Basin ecological conditions. The "below Willow Creek" station is in Hope Valley near the headwaters.
QAPP Information: | The quality assurance requirements of the SWAMP QAPP were met.
QAPP Information Reference(s):